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xddd9485
V2EX  ›  机器学习

numpy 转 torch , GPU 并行计算

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  •   xddd9485 · 213 天前 · 991 次点击
    这是一个创建于 213 天前的主题,其中的信息可能已经有所发展或是发生改变。

    代码小白, 写代码的时候直接使用 numpy , 没考虑到之后要用 GPU

    目前是打算用 Colab 跑这些代码

    求各位大神帮帮忙, 怎么改动才能把这些需要多次调用的函数使用 GPU 计算 (在后面的代码中也会用到 PSO 之类的东西)



    import numpy as np
    import pandas as pd
    
    import warnings
    warnings.filterwarnings('ignore')
    
    
    # @title 阴影确定
    
    # ### 1]. 判断点是否在阴影内
    # Displaying all the modified functions
    def is_left(P0, P1, P2):
        """Determine if point P2 is to the left of the line segment from P0 to P1."""
        return (P1[0] - P0[0]) * (P2[1] - P0[1]) - (P2[0] - P0[0]) * (P1[1] - P0[1])
    
    # 绕射法判断点是否在多边形内部
    def winding_number_revised(P, polygon_corners):
        """Revised winding number function."""
        wn = 0
        num_vertices = len(polygon_corners)
    
        # Iterate through the edges of the polygon
        for i in range(num_vertices - 1):
            if polygon_corners[i][1] <= P[1] < polygon_corners[i+1][1]:  # Upward crossing
                if is_left(polygon_corners[i], polygon_corners[i+1], P) > 0:
                    wn += 1
            elif polygon_corners[i+1][1] <= P[1] < polygon_corners[i][1]:  # Downward crossing
                if is_left(polygon_corners[i], polygon_corners[i+1], P) < 0:
                    wn -= 1
    
        # Convert wn to binary (inside/outside) value
        return 1 if wn != 0 else 0
    
    
    
    # ### 2]. 角点计算
    # 角点排序
    def sort_corners(unsorted_corners, center):
        """Sort corners in counter-clockwise order."""
        vectors = [np.array(corner) - np.array(center) for corner in unsorted_corners]
        angles = [np.arctan2(vector[1], vector[0]) for vector in vectors]
        sorted_corners = [corner for _, corner in sorted(zip(angles, unsorted_corners))]
        return sorted_corners
    
    # 确保凸四边形的情况下计算角点
    def debug_compute_corners_corrected(center, normal, K, L):
        """Compute corners ensuring they form a convex parallelogram."""
        v = np.array([0, 0, 1])  # Assuming z-axis as a reference vector
        if np.allclose(normal, v) or np.allclose(normal, -v):  # If normal is aligned with z-axis, take another reference
            v = np.array([1, 0, 0])
    
        dir1 = np.cross(normal, v)
        dir1 = dir1 / np.linalg.norm(dir1)
        dir2 = np.cross(normal, dir1)
        dir2 = dir2 / np.linalg.norm(dir2)
    
        half_K = K / 2
        half_L = L / 2
        corner1 = center + half_K * dir1 + half_L * dir2
        corner2 = center + half_K * dir1 - half_L * dir2
        corner3 = center - half_K * dir1 - half_L * dir2  # Swapped the ordering to ensure convex shape
        corner4 = center - half_K * dir1 + half_L * dir2  # Swapped the ordering to ensure convex shape
    
        return corner1, corner2, corner3, corner4
    
    # 存储角点
    def compute_matrix_corners_sorted_v4(data, K, L):
        """Computes the matrix corners with the corrected function and includes z-coordinates."""
        corners = data.apply(lambda row: debug_compute_corners_corrected([row["x(m)"], row["y(m)"], row["z(m)"]],
                                                                         [row["x_normal"], row["y_normal"], row["z_normal"]],
                                                                         K, L), axis=1)
    
        # Sort the corners
        corners = corners.apply(lambda x: sort_corners(x, [0, 0, 0]))
    
        data['Corner1_x'] = corners.apply(lambda x: x[0][0])
        data['Corner1_y'] = corners.apply(lambda x: x[0][1])
        data['Corner1_z'] = corners.apply(lambda x: x[0][2])
        data['Corner2_x'] = corners.apply(lambda x: x[1][0])
        data['Corner2_y'] = corners.apply(lambda x: x[1][1])
        data['Corner2_z'] = corners.apply(lambda x: x[1][2])
        data['Corner3_x'] = corners.apply(lambda x: x[2][0])
        data['Corner3_y'] = corners.apply(lambda x: x[2][1])
        data['Corner3_z'] = corners.apply(lambda x: x[2][2])
        data['Corner4_x'] = corners.apply(lambda x: x[3][0])
        data['Corner4_y'] = corners.apply(lambda x: x[3][1])
        data['Corner4_z'] = corners.apply(lambda x: x[3][2])
    
        return data
    
    
    
    # ### 3]. 反射光线计算
    # 每枚镜子反射光线计算
    def compute_reflected_light_direction(V, B, data_with_plane_equation):
        """Compute the direction of the reflected light."""
        # 通过镜子座标检索 data_with_plane_equation 中对应的镜子法向量
        matching_row = data_with_plane_equation[(data_with_plane_equation["x(m)"] == B[0]) &
                                                (data_with_plane_equation["y(m)"] == B[1]) &
                                                (data_with_plane_equation["z(m)"] == B[2])]
    
        if matching_row.empty:
            return None
    
        # 提取镜子的法向量
        normal = np.array([matching_row["x_normal"].values[0],
                           matching_row["y_normal"].values[0],
                           matching_row["z_normal"].values[0]])
    
        # 计算反射光线的方向向量
        V_reflected = V - 2 * np.dot(V, normal) * normal
    
        return V_reflected
    
    
    # ### 4]. 交点转化判断
    # 计算平面方程
    def compute_plane_equation(data):
        """Compute the equation of the plane for each mirror."""
        A_values, B_values, C_values, D_values = [], [], [], []
        for index, row in data.iterrows():
            P1 = np.array([row["Corner1_x"], row["Corner1_y"], row["Corner1_z"]])
            P2 = np.array([row["Corner2_x"], row["Corner2_y"], row["Corner2_z"]])
            P3 = np.array([row["Corner3_x"], row["Corner3_y"], row["Corner3_z"]])
            v1 = P2 - P1
            v2 = P3 - P1
            n = np.cross(v1, v2)
            D = -np.dot(n, P1)
            A_values.append(n[0])
            B_values.append(n[1])
            C_values.append(n[2])
            D_values.append(D)
        updated_data = data.copy()
        updated_data['A'] = A_values
        updated_data['B'] = B_values
        updated_data['C'] = C_values
        updated_data['D'] = D_values
        return updated_data
    
    # 计算线面交点
    def compute_intersection(P0, d, plane_equation):
        """Compute the intersection point of line and plane."""
        A, B, C, D = plane_equation
        n = np.array([A, B, C])
        P0 = np.array(P0)
        t = -(np.dot(n, P0) + D) / np.dot(n, d)
        intersection = P0 + t * d
        return intersection
    
    # 计算反射光线
    def reflective_light_function_v2(x, y, z, d, plane_equation_df):
        """Determine if light is reflected from a given point to the viewer."""
        for _, row in plane_equation_df.iterrows():
            A, B, C, D = row['A'], row['B'], row['C'], row['D']
            corners = [
                (row["Corner1_x"], row["Corner1_y"]),
                (row["Corner2_x"], row["Corner2_y"]),
                (row["Corner3_x"], row["Corner3_y"]),
                (row["Corner4_x"], row["Corner4_y"]),
                (row["Corner1_x"], row["Corner1_y"])
            ]
            P0 = [x, y, z]
            intersection_point = compute_intersection(P0, d, (A, B, C, D))
            if winding_number_revised(intersection_point[:2], corners):
                return 1
        return 0
    
    
    # ### 5]. 功能函数
    # Displaying the remaining modified functions
    def find_points_in_hemisphere(B, df, R):
        """Find mirrors that are within a hemisphere facing point B."""
        x_B, y_B, z_B = B.flatten()  # Flattening to ensure it's a 1D array
        vec_OB = np.array([x_B, y_B, z_B])
        rows_list = []
    
        for index, row in df.iterrows():
            x, y, z = row['x(m)'], row['y(m)'], row['z(m)']
            vec_P = np.array([x - x_B, y - y_B, z - z_B])
            distance_to_B = np.linalg.norm(vec_P)
            dot_product = np.dot(vec_OB, vec_P)
    
            if distance_to_B <= R and dot_product < 0:
                new_row = {
                    'x(m)': row['x(m)'],
                    'y(m)': row['y(m)'],
                    'z(m)': row['z(m)'],
                    'x_normal': row['x_normal'],
                    'y_normal': row['y_normal'],
                    'z_normal': row['z_normal']
                }
                rows_list.append(new_row)
    
        df_inside_hemisphere = pd.DataFrame(rows_list)
        return df_inside_hemisphere
    
    # 分块扫描并记录
    def block_scanning(data_all, data, plane_equation_data, V, num_blocks, K, L):
        """Block scanning function with corrected corner computations."""
        blocks = np.zeros((num_blocks, num_blocks))
    
        matching_row = data_all[(data_all["x(m)"] == data[0]) &
                                (data_all["y(m)"] == data[1]) &
                                (data_all["z(m)"] == data[2])]
    
        if matching_row.empty:
            return None
    
        normal = np.array([matching_row["x_normal"].values[0], matching_row["y_normal"].values[0], matching_row["z_normal"].values[0]])
        center = np.array([matching_row["x(m)"].values[0], matching_row["y(m)"].values[0], matching_row["z(m)"].values[0]])
    
        # Compute corners using the corrected function
        corner1, corner2, corner3, corner4 = debug_compute_corners_corrected(center, normal, K, L)
    
        corners = [corner1, corner2, corner3, corner4]
    
        dir1 = np.array(corner2) - np.array(corner1)
        dir2 = np.array(corner4) - np.array(corner1)
    
        step1 = dir1 / num_blocks
        step2 = dir2 / num_blocks
    
        d = compute_reflected_light_direction(V, data, data_all)
    
        for i in range(num_blocks):
            for j in range(num_blocks):
                block_center = np.array(corner1) + (i + 0.5) * step1 + (j + 0.5) * step2
                x, y, z = block_center
    
                A, B, C, D = matching_row["A"].values[0], matching_row["B"].values[0], matching_row["C"].values[0], matching_row["D"].values[0]
                z = (-D - A*x - B*y) / C
    
                # The reflective light function is omitted for now, but can be added back.
                result = reflective_light_function_v2(x, y, z, d, plane_equation_data)
                blocks[i, j] = result
    
        ratio = np.sum(blocks) / np.size(blocks)
        return ratio
    
    3 条回复    2023-10-02 14:05:35 +08:00
    Muniesa
        1
    Muniesa  
       212 天前 via Android
    先试试 cupy 吧,改成 torch 需要把 ndarry 换成 tensor ,数学运算要换成 torch 版本的,有的操作 torch 不支持可能还要转回 numpy 来算
    lbingl
        2
    lbingl  
       212 天前 via Android
    让 GPT 帮你转换
    hsfzxjy
        3
    hsfzxjy  
       212 天前 via Android
    用 jax ?
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